1. Field of the Invention
The present invention relates to a compressor for compressing a refrigerant in a refrigeration circuit included, for example, in an air conditioning system for a vehicle.
2. Description of the Related Art
For instance, a compressor of this type is disclosed in Unexamined Japanese Patent Publication No. 2001-295767. The compressor disclosed in this publication includes a housing and a scroll-type compression unit that is accommodated in the housing. The compression unit sucks a refrigerant introduced into the housing to compress the refrigerant, and discharges a compressed refrigerant through a discharge hole into a discharge chamber defined in the housing. A high-pressure refrigerant in the discharge chamber is delivered from a delivery port of the housing toward a condenser disposed in a refrigeration circuit.
In general, the refrigerant used in the refrigeration circuit contains lubricating oil. The lubricating oil serves for lubrication of various moving parts and sliding parts in the compressor. The lubricating oil contained in the refrigerant, however, deteriorates the refrigeration performance of the refrigeration circuit. Therefore, the compressor described in the above publication further includes an oil separator for lubricating oil. This oil separator separates part of the lubricating oil from the compressed refrigerant in the process where the compressed refrigerant is led from the discharge chamber to the delivery port of the housing. As a result, the lubricating oil content of the refrigerant that is delivered from the compressor is low, so that the refrigeration circuit can display the desired refrigeration performance.
In addition, the lubricating oil separated by the oil separator is mixed into the refrigerant in the housing and recycled for lubricating the moving parts and the sliding parts.
The oil separator includes a separation chamber located between the discharge chamber and the delivery port. The separation chamber restricts the disposition of the delivery port. In other words, the delivery port has to be disposed near the separation chamber.
A compressor of this type includes various safety devices. The compressor disclosed in Unexamined Japanese Patent Publication No. 2000-220587 has a pressure relief valve functioning as a safety device. When the pressure in the discharge chamber is abnormally raised, the pressure relief valve is opened to discharge the high-pressure refrigerant in the discharge chamber outside the compressor.
The compressor disclosed in Unexamined Japanese Utility Model Publication No. 7-14189 has a thermal protector functioning as a safety device. If the temperature in the discharge chamber is abnormally increased, the thermal protector outputs an error signal. The output of the error signal causes the driving of the compression unit to stop.
The pressure relief valve and the thermal protector are attached to respective portions of a housing wall that demarcates the discharge chamber. Consequently, the attachment of the pressure relief valve and the thermal protector requires an attachment opening and a recess to be formed in the wall of the housing. Moreover, components, such as seals and fixing screws, are indispensable.